1. Field of the Invention
The invention relates to an insulated-gate bipolar transistor (IGBT).
2. Description of Related Art
Japanese Patent Application Publication No. 2010-114136 (JP 2010-114136 A) describes an IGBT that has gate electrodes formed in trenches. In this IGBT, the gate electrodes extend in stripes. That is, the gate electrodes extend straight in parallel to each other.
In order to reduce the loss that occurs in an IGBT, it is preferable to reduce the on-resistance of the IGBT. With an IGBT that has gate electrodes that extend in stripes, as in JP 2010-114136 A, the on-resistance can be reduced if the mesa width (i.e., the interval between adjacent gate electrodes) is reduced. However, to reduce the mesa width, a manufacturing process in which fine processing is possible is necessary, which ends up increasing the manufacturing cost of the IGBT.